The Ancient or Forgotten ones in the short stories of H.P. Lovecraft came from Sirius in a giant migration.
The Dogon tribe near Timbuktu in Africa have strange stories concerning Sirius - that visitors from the binary star system (e.g. if the Sun were to have another star right next to it and earth revolved around it too) visited them. Still unexplained, the people of this remote tribe knew of Sirius's sister star - a white dwarf that was undected until the 1970s. The Dogon say their astronomical knowledge was given to them by the Nommos, amphibious beings sent to earth from Sirius for the benefit of mankind. The name comes from a Dogon word meaning "to make one drink," and the Nommos are also called Masters of the Water, the Monitors, and the Teachers.